PROBLEM TO BE SOLVED: To provide monoclonal antibodies or antibody fragments to canine IL-6 receptor, to provide diagnostic agents of canine arthropathy or arthritis, to provide diagnostic methods of canine arthropathy or arthritis, to provide therapeutic agents of canine arthropathy or arthritis, to provide therapeutic methods of canine arthropathy or arthritis, as well as to provide nucleic acids and vectors.SOLUTION: The invention relates to a monoclonal antibody or antibody fragment to canine interleukin 6 receptor, wherein CDR 1-3 have heavy chain variable regions respectively consisting of an amino acid sequence of SEQ ID NO: 1-3, or of an amino acid sequence in which one or some amino acids are deleted, substituted, or added in the amino acid sequence of SEQ ID NO: 1-3, and CDR 1-3 have light chain variable regions respectively consisting of an amino acid sequence of SEQ ID NO: 4-6, or of an amino acid sequence in which one or some amino acids are deleted, substituted, or added in the amino acid sequence of SEQ ID NO: 4-6.SELECTED DRAWING: NoneCOPYRIGHT: (C)2017,JPO&INPIT【課題】イヌIL-6受容体に対するモノクローナル抗体又は抗体フラグメントを提供する。また、イヌの関節症又は関節炎の診断剤、イヌの関節症又は関節炎の診断方法、イヌの関節症又は関節炎の治療剤、イヌの関節症又は関節炎の治療方法、核酸及びベクターを提供する。【解決手段】CDR1~3が、それぞれ配列番号1~3のアミノ酸配列又は配列番号1~3のアミノ酸配列において1若しくは数個のアミノ酸が欠失、置換若しくは付加されたアミノ酸配列からなる重鎖可変領域、及び、CDR1~3が、それぞれ配列番号4~6のアミノ酸配列又は配列番号4~6のアミノ酸配列において1若しくは数個のアミノ酸が欠失、置換若しくは付加されたアミノ酸配列からなる軽鎖可変領域、を有する、イヌインターロイキン-6受容体に対するモノクローナル抗体又は抗体フラグメント。【選択図】なし
